Trip : I don't see your objection to kids getting hold of flowers . Maybe that's because I'm old & remember the " flower children " ( LOL) .
I had been wondering how paraphrenalia sellers could skirt the law ! I remember cheap automatic knives being sold in kit form . The " ballistic knife" was sold minus the spring, a part you can get at any hardware store - if you can find a hardware store .
I think the appeal of brass knucks is that you can use them as a sneaky way to win a fistfight while knife fighting is playing for keeps .
To ward off an attack, something with reach is better ( c-cell Maglite, expandable baton, hickory tire checker / mini aluminum baseball bat , knife, Surefire flashlight with striking head etc. ).
Brass knucks are probably illegal for the same reason as switchblades are : Some politician dreamed that bad guys would stop harming people if you banned their weapons , weapons they thought had no good purpose ( though you would expect politicians to value a good paperweight LOL ).

Actual use story : A security guard was challenged to a fight . He removed his duty belt complete with .38 revolver and went outside to fight . His opponent had brass knuckles and won the fight ...plus they fired the guard .

Trip :
I think the appeal of brass knucks is that you can use them as a sneaky way to win a fistfight while knife fighting is playing for keeps .

Brass Knucks can, have, and do, kill when used by people that do not know how to use them. It is pretty much the same thing with blackjacks.

All of that said, if brass knucks were legal to own and carry, I would own and carry them along with a blackjack. When used correctly, they can stop a fight quickly and without doing much permanent damage.

Unfortunately, in most states, blackjacks, saps, and brass knuckles are in the same category as switchblades in the mind of the politicians. Only the truly evil ones would own, carry or use them. For that matter, in many states, whatever you carry as a weapon is considered a weapon if you use it on someone and not often covered by concealed carry permits. Apparently, it is more moral to shot someone than to thump their wrist with a blackjack....

LEOs are exempt of course and are expected to make decisions about what level of force to use, except for brass knucks which I don't think even LEOs can legally carry or use.

Brass Knucks can, have, and do, kill when used by people that do not know how to use them. It is pretty much the same thing with blackjacks.

All of that said, if brass knucks were legal to own and carry, I would own and carry them along with a blackjack. When used correctly, they can stop a fight quickly and without doing much permanent damage.

Unfortunately, in most states, blackjacks, saps, and brass knuckles are in the same category as switchblades in the mind of the politicians. Only the truly evil ones would own, carry or use them. For that matter, in many states, whatever you carry as a weapon is considered a weapon if you use it on someone and not often covered by concealed carry permits. Apparently, it is more moral to shot someone than to thump their wrist with a blackjack....

LEOs are exempt of course and are expected to make decisions about what level of force to use, except for brass knucks which I don't think even LEOs can legally carry or use.

What is a black jack? And how do you hit some one with brass knuckles and not cause serious damage?